This invention relates to multilamp photoflash units and, in particular, to a more compact, cost-efficient array of photoflash lamps, having ahousing with enhanced containment strength.
Heretofore, multilamp photoflash units, of either the cube or array configurations, have comprised at least two separate housing sections joined together. For example, in the case of the flashcube, such as described in U.S. Pat. No. 3,327,105, the magicube, such as described in U.S. Pat. No. 3,730,669, and the flash bar, such as described in U.S. Pat. No. 3,857,667, a plurality of lamps and associated reflectors are mounted on a relatively horizontal base member and enclosed in a cubical or rectangular parallelopiped-shaped transparent cover section which is joined to the periphery of the base section by means of heat or sonic sealing techniques. In the case of the flash bar, which is a bi-directional linear array, the lamps are connected to a printed circuit board which is held in the separate base member.
In a unidirectional linear photoflash array described in U.S. Pat. No. 3,473,880 of Wick, the lamps are connected to a printed circuit board which comprises the rear housing of the unit and includes reflector cavities. A separate transparent sheet is then secured to the front of the Wick unit to enclose the lamps. Circuit patterns and terminals are disposed on both sides of this rear housing member, and one of the lamp lead-in wires passes through an aperature in the rear housing reflector cavity for connection to a circuit pattern on the exterior of the rear side of the housing. U.S. Pat. No. 3,430,545 of Wick appears to illustrate a somewhat similar type of housing structure.
U.S. Pat. Nos. 3,894,226 and 4,017,728 illustrates a currently marketed planar photoflash array referred to as a flip flash. The overall construction of the flip flash unit comprises front and back plastic housing members with interlocking means for providing a unitary structure. The front housing member is a rectangular concavity, and the back housing is substantially flat. Sandwiched between the front and back housing members, in the order named, are a plurality of flashlamps, a multi-cavity reflector member, an insulating sheet, a printed circuit board having conductive patterns on one side to which the lamps are connected, and an indicia sheet. A similar planar array in which additional lamps are packaged in the same volume is described in U.S. Pat. No. 4,164,007.
Another planar array of photoflash lamps is described in U.S. Pat. No. 3,608,451 of Kelem, which illustrates an unenclosed circuit board having a connector tab at the bottom edge and a plurality of lamps connected to a conductive pattern which includes a flat reflector foil disposed on the surface of the circuit board. There is no enclosure housing shown in Kelem. U.S. Pat. No. 3,598,985, in FIG. 6, illustrates a combined reflector circuit board arrangement which is bidirectional and has an undulating reflector configuration. FIGS. 7 and 8 of the last-mentioned patent illustrate a folded terminal board reflector combination to provide a bidirectional configuration, the fold line being located along the center of the connector tab. The housing for the embodiments shown in U.S. Pat. No. 3,598,985 comprises a base section and a separate transparent cover section, similar to that described above with respect to the flash bar.
In U.S. Pat. No. 4,245,280 a compact, cost-efficient photoflash unit is described comprising a vertical linear array of flash lamps mounted on a printed circuit strip disposed within a longitudinal channel of an elongated rear housing member. A separate transparent cover panel is attached to the front of the housing member for enclosing the flash lamps. To provide structural rigidity, the cover has rectangular corner posts at each end and a transverse web at the center which engage slots in the housing and are secured by ultrasonic welding. The longitudinal edges are secured by a plurality of cylindrical posts along each side of the cover which fit into matching holes in the housing and have rivet heads formed in the ends as provided by ultrasonic heating and pressure.